This invention relates generally to surgical instruments. More particularly, this invention relates to endoscopic surgical instruments having end effectors with a stationary element and a articulating element.
The endoscopy and laparoscopy procedures have recently become widely practiced surgical procedures. A laparoscopy procedure typically involves incising through the navel and through the abdominal wall for viewing and/or operating on the ovaries, uterus, gall bladder, bowels, appendix, although more recently, incisions and insertion of trocar tubes have been made in different areas of the abdomen and even in the chest cavity. Typically, trocars are utilized for creating the incisions. Trocar tubes are left in place in the abdominal wall so that laparoscopic surgical tools may be inserted through the same. A camera or magnifying lens is often inserted through the largest diameter trocar tube (e.g. 10 mm diameter) which is generally located at the navel incision, while a cutter, dissector, or other surgical instrument is inserted through a similarly sized or smaller diameter trocar tube (e.g. 5 mm diameter) for purposes of manipulating and/or cutting the internal organ. Sometimes it is desirable to have several trocar tubes in place at once in order to receive several surgical instruments. In this manner, organ or tissue may be grasped with one surgical instrument, and simultaneously may be cut or stitched with another surgical instrument; all under view of the surgeon via the camera in place in the navel trocar tube.
Different classes of endoscopic and laparoscopic tools are known in the art, including cutters (scissors), dissectors, graspers, clamps, etc. Among the classes of tools, it is known that tools can be double acting or single acting; i.e., either both of the end effectors at the end of the tool move (double acting), or only one of the end effectors move (single acting). Previous to the present invention, the single acting instruments of the art incorporated the stationary end effector as an integral element of the clevis of the instrument. Examples of such single acting instruments where the stationary end effector is integral with the clevis include a claw forceps, straight scissors, and a hook scissors, all of which are disclosed in Chapter 2 ("Laparoscopic Equipment and Instrumentation" by Talamini and Gadacz) of Surgical Laparoscopy, edited by Karl A. Zucker, Quality Medical Publishing, Inc., St. Louis, Mo. (1991). While the prior art design of incorporating the stationary end effector with the clevis has been effective in obtaining the desired result, i.e., that only a single end effector moves, the design is expensive to manufacture (typically being stainless steel). The expensive nature of the instrument, however, does not lend itself to permitting disposal of the instrument after one use, and disposable instruments are becoming standard in the art due to the difficulty in sterilizing endoscopic and laparoscopic instruments and the risk of spreading disease.